In a mobile wireless device, a wide band and high gain characteristics must be ensured by stabilizing an antenna current flowing through housings and circuit boards in accordance with the wavelength.
In a foldable mobile wireless device, antenna current flows in a coaxial cable and the like that electrically connects circuit boards provided inside two housings.
Since the coaxial cable and the like passes via a hinge for joining the two housings, it is difficult to ensure a large ground-contact area. This leads to a problem that the coaxial cable and the like functions as a coil at high frequencies. Furthermore, since the antenna current and its return current flow in the coil cable and the like, there is also a problem of reverse-phase cancellation of the antenna current.
To avoid such problems, as disclosed in Patent document 1, conductors connected to a reference potential section (ground) of each circuit board are provided at base ends of two housings (hinge vicinity), and antenna current is flowed through them by capacitance-coupling them at high frequency, thereby avoiding cancellation and the like of antenna current.
[Patent document 1] Japanese Unexamined Patent Application, First Publication No. 2006-54843